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Abstract This investigation was conducted at ShandaweelAgricultural Research station, Sohag Governorate, Egypt, during 1981 and 1982 seasons. The investigation included two studies. First study : Four field experiments were carried out to study the effect of intercropping soybean with short and tall grain sorghum cultivars under three plant population densities of either sorghum or soybean on the equantiative and qualitative characters of both crops The experimental design was factorial in a randomized complete blocks in four replicates. Each experiment included 36 treatments drived from a combination of four cropping systems 2 intercropping patterns (1:1, 2:1 sorghum:soybean) respectively compared with pure stand of each crop at three densities for each crop. (100,78, and 61% for sorghum and 100, 67, and 50% for soybean). Each plot had six ridges of 3.5 m long and 60 cmapart in an areB of 12.60 m • The normal cultural practices for growing each crop were applied. Soybean was sown two weeks before sorghum planting. The two associated crops were harvested at the physiological maturity of each. Results could be summarized as follows: Effect of intercropping patterns and popUlation densities of sorghum and soybean on growth measurementst A) Plant height of sorghum. and soybean _ Any of the applied intercropping patterns produced shorter sorghum plants than the pure stand. However, the magnitude ~aS slightlY greater ~ith tall sorghum as cOlllpared~i th the short type. whereas soybean plant height ~as increased by intercropping patterns than the pure stand. Plant height of sorghum was not affected by sorghum population densities, ~hereas, increasing soybean population densit·ies 01: the intercropped soybean 1 : rom 700 to 140000 plants/1:ad increased the height 01 : either sorghum or Soybean plants signi1:ican tB) Number of long lasting active leaves ofsorghum per plant _ Both of the applied intercropping patterns produced Signi1:icantlY higher.number 01:long lasting ective leaves/plant compared ~ith the pure stand. _ As sorghum population densities decreased, the number 01:long lasting active. leaves 01:either short or tall sorghum plants ~ere increased. whereas, soybean population densities increased the number 01:active l.eaves/short or tal.l.sorghum plant. This increases ~ere signif1can t · The interaction effect of the tntercropping patterns and sorghum population densities ~as not signi1:ican tc) Leaf/stem ratio: -, _ There.as no specifio effect of the leaf / stem ratiO 1:or either short or tall.sorghum at the varioUS intercropping patterns and sorghum or soybean population densities.D) Leaf area index (L.A.I.) of sorghum and soybean _ Pure stand of sorghum produced the lowest L.A.I. than intercropped ones with a significant differences. whereas, intercropped soybean with either short or tall sorghum significantly reduced L.A.I. as compared with the soybean in pure stand. _ As plant population densities of sorghum and soybean increased L.A.I. of each of the associated crops were increased Significantly. No significant interaction effect of the various intercropping patterns and sorghum population densities on L.A.!. of sorghum, and significant interaction effect of the various intercropping patterns and soybean population densities on ~.A.I. of soybean. E) Number of branches/soybean plant: _ Number of branches/soybean plant decreased significantlY by the various intercropping patterns intercropped with either short or tall sorghum than the soybean in its pure stand. _ The number of branches/soybean plant were increased as the plant population densities of any of the associated crops decreased. The interaction effect of the intercropping patterns and soybean densities was significant on number of branches/plant. Effect of intercropping patterns and different EOEulation densities on yield and yield compo;ents ofsorghum and soybean _ Yield components _ Sorghum F) Head length and ”,idth _ Intercropping pattern 1 : 1 produced longer and wider head than 2 : 1 pattern and/or the pure stand with significant differences ~ith pure stand only. _ As sorghum population densities increased head length and width were decreased simultaneously.whereas, soybean population densities showed an opposite results than what waS mentioned with sorghum population densities. G) Number of grains and grain weight/head. and lOOO-grain weight Intercropping patterns. significantly increased number of grains and grain ~eight/head, and lOOO-grain weight as compared with the pure sorghum stand. _ The lighter population densities of short or tall sorghum and the heaviest soybean population densities produced the highest number of grainS/head, grain weight/head, and 1000 grains weight significantly. _ The interaction effect of intercropping patterns and population densities of sorghum or soybean was significant. -Soybean : H) Number of pods and seed weight/plant. an.9 = lOOO-seed weight Intercropping patterns significantly ecreased number of pods and seed weight/plant, and lOOO-seed weight as compared with the pure stand. _ The l~ghter the population densities of short or tall sorghum and/or soybean produced the highest number of pods/plant, seed weight/plant, and 1000-seed weight of soybean. The interaction effect of intercropping patterns and sorghum or soybean papulation densities was significant. Yield: I) Biomass yield of sorghum and soybean (on dry:matter basis): _ Any of the two applied intercropping patterns produced significantly higher sorghum and lower soybean biomass dry matter yield than their pure stands. _ As the population densities of short or tall sorghum and/or soybean, increased, the biomass dry yield of either sorghum or soybean was increased. The obtained increase in sorghum biomass dry yield was 22.4 and 39.7% with short and tall sorghum cultivars, respectively and the biomass dry yield of soybean was 45.5 and 67.4% when intercropping with short and tall sorghum by increasing the population densities from 70000 to 140000 plant/fad_ The interaction effect of the intercropping patterns and sorghum or soybean population densities was significant. J) Grain yield of sorghum : Intercropping patterns produced significant~Yhigher grain yie~d of sorghum than its pure stand. Intercropping pattern 1 : 1 produced significantly higher grain yield than 2 : 1 by 12.3% with short cultivar, whereas, 1:1 pattern produced 23.3% higher grain yield than the pure stand, corresponding to 9.2 and 19.9%, respectivelY for tall sorghum. As sorghum population densities increased, grain sorghum yield of either short or tall cultivars was increased. This increase was 12.6 and 15.0% as the sorghum population density increased from 56000 to 72000 and from 72000 to 92000 plant/fad respectively with short sorghum, being 17.2 and 10% for tall sorghum. The interaction between intercropping patterns and short sorghum population densities was not significant and for tall sorghum was significant on grain yield of sorghum. The interaction effect of the intercropping patterns and soybean population densities was significant on grain yield of sorghum. Soybean was more productive in its pure stand than 1:1 intercropping pattern with sorghum which in turn more productive than 2:1 pattern with a significant differences in soybean seed yie1d, and more soybean seed Soybean seed yield productivity was obtained in esse of intercropping with short rather than the tall cultivars. There was a continuous and significant increase in soybean seed yield as the soybean population densities increased from 70000 to 94000, and up to 140000 plant/fad when intercropped with short or tall sorghums- and by increasing the population density from 70000 to 140000 plant/fad Soybean seed yield was increased by 43.) and 42.9% when intercropped with short and tall sorghum, respectively- Interaction effect of intercropping patterns and sorghum or soybean population densites waBsignificant on soybean seed yield. The highest stover yield was produced by using 1 : 1 intercropping pattern which was higher than the pure stand by 26.6 and2l.7% with short and tall sorghum respectively. stover yield of sorghum: - By increasing population density of short sorghum from 56000 to 92000 plant/fad and the tall sorghum from 44000 to 72000 plant/fad the obtained increase in stover yield was 41.7% and 38.8%, respectively- It also clear that increasing soybean plant population densities increased stover yield of sorghum significantly. The interaction effect between intercropping patterns and sorghum or soybean population densities was significant • 0) Crude protein percentage and crude protein yield of soybean Pure stand of soybean produced significantly higher cp yield than when intercropped with any the applied cropping patterns. Crude protein yield was increased in soybean seed significantly as soybean population densities increased from 70000 to 140000 plant/fad. pl\, 011 percentage and oil yield of soybean Soybean oil yield was significantly increased in pure stand than when intercropped at any pattern the first pattern 1 : 1 produced higher oil yield than the second 2 : 1 pattern significantly in association, with either short or tall sorghum. Oil yield of soybean was significantly increased as the soybean population density increased either when the intercropped sorghum was short or tall. Effect of intercropping patterns and different population densities of sorghum and soybean on the competitive relationships. R) Land equivalent ratio (LER) of sorghum Vias higher than that of soybean,and intercropping pattern 1:1 had a higher LER than 2:1 pattern when either short or tall sorghum was associated with soybean. Land equivalent ratio increased by decreasing sorghum and increasing soybean population densities. S) Relative crowding coefficient (RCC) increased by increasing soybean population densities and decreas~ that of sorghum. However the obtained RCC was higher when using short sorghum than the tall one.T) Aggressivity of sorghum was higher (dominant) than soybean (dominated) in the two intercropping patterns and increased by increasing the population densities of the associated crops sorghum and soybean. The economic return (net income in EgyPtian pounds) from intercropping patterns and different population densities of sorghum and soybean: U) The net income increased by using intercropping pattern 1:1 than 2:1 and by increasing the population densities of the associated crops sorghum and soybean. Second study : Four field experiments were carried out to study the effect of intercropping forage cowpea with short and tall sorghum cultivars on the quantitative and qualitative characters of both crops. Each experiment included five treatments. three intercropping patterns in alternative ridges of 1:1, 2:1 and 3:1 of sorghum : cowpea respectively and compared with the pure stand for each crop. The five treatments were layed out in randomized complete blocks design in four replicates. Each plot had 12 ridges of 3.5 m long and 60 cm apart in an area of 25.20 m2• Cowpea was sown two weeks early before sorghum and the normal cultural practices for growing each crop were applied. Grain sorghum was harvested at physiOlogical maturity. whereas two cuts .ere taken from forage cowpea.Results could be summarized as follows : Effect of varioUS interaro atterns of fora e cow ea and sorghum on growth measurements of the associated cropS. sorghum:.A Plant height of either short or tall sorghum was not significantly affected by any of the applied intercropping patterns with cowpea. B Intercropping patterns of sorghum and cowpea produced the highest number of long lasting active leaves/sorghum plant as compared with sorghum in pure stand. C Leaf/stem ratio of sorghum plant was higher in pure stand of sorghum than when intercropped with cowpea having a significant effect when using short sorghum cultivar. D Leaf area index of either short or tall sorghum culting was significantlY affected by the applied intercropping patterns with forage cowpea, where 1:1 intercropping pattern produced the highest L.A.I. as compared with the other patterns and pure stand as well. Forage cowpea E There .as a significant tendency fo the production of shorter cowpea plants as the associated short arta1l sorghum plantsyincreased in the pattern. F Number of branches per cowpea plant was significantly higher in pure stand as compared with the various intercropping patterns when using either short or tall sorghum cultivar. Higher number of leaves per cowpea plant was significantly produced from pure stand as compared with the applied intercropping patterns using short or tall sorghum. H The highest leaf area index was significantly obtained from cowpea in pure stand as compared with the other applied intercropping patterns. I _ Fresh and dry weight per cowpea plant were higher in pure stand of cowpea as compared with any of the applied intercropping patterns using either short or tall sorghum cultivar. The obtained values were relativelY higher in the first than the second cut. Effect of various intercro atterns of sor urnnd cowpea on the yield components of sorghum ~ _ Head length of either short or tall sorghum cultivar was increased when using the various intercropping patterns with forage cowpea as compared with pure stand especiaDywhen using tall sorghum where the differences were significant. K _ Head width of short and tall sorghum was increased significantly by intercropping with forage cowpea as compared with their pure stand. L _ Number of grains/head of sorghum was significantly increased for short sorghum cultivar by the applied intercropping patterns with forage cowpea as compared with its pure stand. M Grain weight/head and IOOO-grain weight of either short or tall sorghum in pure stand produced signifioantly lower values of these characters as compared with any of the applied intercropping patterns. Effect of various intercropping patterns of sorghum and cowpea on the actual and adjusted yield of the associated crops. Sorghum : B Intercropping pattern 1:1 significantly produced the highest adjusted grain yield of short and tall sorghum as compared with their pure stands.o stover adjusted yield of short and tall sorghum Was significantly increased when using the applied intercropping patterns than their pure stands. whereas, intercropping pattern 1:1 produced the highest adjusted stover yield of sorghum. p Lowest adjusted biomass dry yield of either short or tall sorghum was obtained from their pure stand compared with any of the applied intercropping patterns. Forage cowpea : R _ Pure stand of forage produced higher fresh and d and total yield than any of patterns when using either owpea significantly yield of obtained two cuts the applied intercropping hort or tall sorghum. Also, there was a sig fresh and dry yield of fora increased in the pattern, r ficant reduction in thee cowpea as sorghum ratio spectively.The fresh and dry yields of forage cowpea were higher in the applied intercropping patterns when using short rather than tall sorghum. This increase in fresh and dry yield was true in the first cut than the second one.Effect of various intercropping patterns of sorghum and cowpea on crude protein percentage and crude protein yield of the associated crops.Grain sorghum: S - Higher crude protein yield of grain sorghum was obtained when the short or tall sorghum cultivars grown in association with forage cowpea as compared with their pure stands, also when using 1:1 intercropping pattern than either 2:1 or 3:1. Forage cowpea : T - Pure stand of forage cowpea produced the highest crude protein yield than when using the applied intercropping patterns. Also intercropping pattern 1:1 produced significantly higher crud protein yield as compared with 2:1 and/or 3:1 pattern. Effect of various intercropping patterns of sorghum and cowpea on the competitive relationships: U - Land eqUivalent ratio (LER) of sorghtUllwas higher than that of cowpea, and increased by increasing sorghum ratio in the pattern. v - The relative crowding coefficients for sorghum, cowpea and their mixture were decreased as the sorghum ratio increased in the pattern from 1:1 to 2:1 and 3:1, respectively. The highest relative crowding coefficients of both sorghum cultivars were obtained when using 1:1 intercropping pattern. ’W - The aggressivity was increased by increasing tall sorghum ratio in the applied patterns. However, opposite trend was obtained when short sorghum was used. It was obviously clear that sorghum was the dominant intercrop component (and cowpea was dominated) over cowpea in all of the applied intercropping patterns. Effect of various intercroppipg patterns of sorghum and cowpea on the economic return (net income in Egyptian pounds). ’X- The intercropping pattern 1:1 was the highest in the net income than 2:1 or 3:1 pattern, its mean the net income was increased by increasing cowpea ratio in the intercropping pattern. The net income was increased when useding short rather than tall sorghum in intercropping patterns. |