Ahmad, Manzoor (2010) Influence Of Ridge Spacing And Plant Density On Productivity Of Different Maize Hybirds. PhD thesis, NWFP Agriculture University, Peshawar .
Two sets of field experiments were conducted each during autumn 2006 and 2007 to investigate the influence of varying ridge spacing and planting density on growth characteristics, agronomic and yield traits, quality of grain, and nutrient up-take patterns of diverse maize (Zea mays L.) hybrids. Another objective was to optimize planting density for good harvests of maize grown on narrow (45 cm and 60 cm) as against conventional (75 cm apart) ridges In Experiment-I three diverse maize hybrids, DK-919 (early maturity), DK-5219 (medium maturity) and Pioneer-30Y 87 (late maturity) were planted at ridges spacing of 45, 60 and 75 cm each. In Experiment-II, maize hybrid DK- 919 was planted at three inter ridge spacing of 45, 60 and 75 cm as main plot and 15, 22.5 and 30 cm intra-ridge spacing imposed as sub plots. Both the experiments were quadruplicated and each sub plot consisted of 6 rows of 7.0 m length. Results revealed that DK-919 recorded total dry matter (17409 kg ha-1) that was 19% and 8% higher than DK-5219 and Pioneer-30Y87, respectively. Maize planted at 45 cm ridge spacing produced 14% and 34 % higher total dry matter than that 60 and 75 cm spaced ridge sown crop. Plant spacing of 15 cm produced 42 and 22% higher dry matter than that recorded for 30 cm and 22.5 cm plant spacing. Early maturing hybrid, DK-919, realized 17 and 6%, higher grain yield than mid and late maturity maize hybrids, respectively. Early and late maize hybrid performed best at 45 cm ridge spacing while mid season hybrid did best at 60 cm ridge spacing. Narrowing the ridge spacing from 75 to 60 cm increased grain yield by 11-18 % while further decrease in ridge spacing from 60 cm to 45 cm resulted in 6-8% increase in grain yield. Decreasing ridge spacing from 75 cm to 45 cm enhanced grain yield by 17-24 % in both the experiments. Reducing intra ridge spacing from 30 cm to 15 cm enhanced grain yield by 25%. Highest grain yield (7606-7027 kg ha-1) was obtained at plant spacing of 60 cm x 15 cm (11 plants m-2) and was followed by 10 plants m-2). DK-919 exhibited higher HI as compared with DK-5219 and Pioneer-30Y87. Harvest indices improved initially with narrowing the plant and ridge spacing but declined when planting densities were increased further. Yield components as number of grains per ear and 1000 grain weight were significantly varied among maize hybrids and with changing ridge and plant spacing during both the growing seasons. Grain yield was linearly related to number of grains per unit area during both the season and regression accounted for about 90-98% of variation in grain yield. Tall and late season hybrid Pioneer 30Y87 exhibited higher LAI values. Differences in LAI between maize hybrids and ridge spacing remained significant throughout growth period and reached the maximum value of 5.33, 5.83 and 6.19 at 45, 60 and 75 cm ridge spacing, respectively. Highest LAI values corresponded to the anthesis time of the crop. Seasonal accumulation of TDM was higher until 60 DAS. Then there was a steady decrease in accumulation of TDM in all the hybrids and at all ridge spacing. Highest seasonal accumulation of TDM was recorded at planting density of 45 cm x 15 cm. Short season hybrid DK-919 had higher NAR than mid or late season hybrid. Narrow rows (45 cm) had higher NAR values than wider ridge spacing.Early maturing maize hybrid DK-919 had higher CGR than that DK-5219 (mid) and Pioneer-30Y87 (late). TDM production was positively and linearly related with total seasonal LAD in both the seasons.Total seasonal LAD explained 98% of variation in TDM production. In general, decreasing ridge and plant spacing enhanced CGR.Pioneer-30Y87 had highest grain oil content when planted at 75 cm ridge spacing. DK-919 had highest grain protein content when planted at 75 cm spacd ridge. DK-5219 and DK-919 planted each at 45 and 60 cm ridge spacing had highest and similar grain starch % than Pioneer-30Y87. Grain oil contents were reduced at narrow ridge and plant spacing (higher planting densities). Highest grain oil content was recorded at wider ridge (75 cm) and plant spacing (30 cm). Grain protein and starch contents decreased with narrow ridge (45 cm) and plant (15 cm) spacing. Results on nutrient uptake patterns revealed that DK-919 recorded higher N, P and K uptake than DK-5219 and Pioneer- 30Y87 at all growth stages. Narrowing the ridge and plant spacing resulted in improved nutrient uptake that was highest at 45 cm ridge and 15 cm plant spacing. On the basis of two years result, it is concluded that maize hybrid DK-919 (early maturing) should preferably be grown at narrow ridges (45 cm) for obtaining high yields. Mid season hybrids like DK-5219 need to be planted at 60 cm ridge spacing while late season hybrid as Pioneer-30Y87 reflected an increasing trend in yield with narrowing ridge spacing in these studies. For higher yield goals, autumn planted hybrid maize can be sown at plant spacing of 60 cm x 15 cm (11 plants m-2).
|Item Type:||Thesis (PhD)|
|Uncontrolled Keywords:||Experiments, Field, Variation, Plant, Influence, Different, Nutrient, Seasonal, Hybirds, Maize, Productivity, Planted, Grain, Yield, Density, Spacing, Ridge|
|Subjects:||Agriculture & Veterinary Sciences(a) > Agriculture(a1)|
|Deposited By:||Mr. Javed Memon|
|Deposited On:||19 Dec 2011 10:37|
|Last Modified:||19 Dec 2011 10:37|
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