Determination Critical Periods of Weed Competition and Weed Control Influence on Yield Productivity of Sweet Pepper (Capsicum annuum L.)

Abstract

Field experiments were carried out at Sids Research Station, Agricultural Research Center during 2016 and 2017seasons to determine the critical period of weed competition in pepper yield and study the effect of some pre-emergence herbicides on controlling weeds and its reflection on yield and its component of pepper. It could be concluded that some safe alternatives to mechanical weed control hand hoeing (twice), are the use of mulching by black polyethylene or reduced rate of pendimethalin (0.850 L.\fed) and butralin (1.25 L.\fed.) for weed control during the pepper crop to produce good fruit yield free from herbicidal residues. Mathematical models between weed-free duration periods were quadric 8.3 and 7.0 weeks from transplanting. The application of pendimethalin at 0.850 l.\feddan supplemented with one hand hoeing and black polyethylene mulch were the best treatments to reduce weed biomass, followed by hand hoeing twice and butralin at 1.25l.\feddan supplemented with one hand hoeing to face weed problem in critical period of weed competition and herbicidal residues in edible pepper fruits were below the maximum residue limit. The relationship between all characters were negatively and significant correlated with weed biomass and positive with pepper fruit yield in both seasons. Practical implications of this research are that planting pepper need weed management in 8 weeks from transplanting from weed competition which can be achieved by either the use of pendimethalin or butralin at a full recommended rates or followed by one hand hoeing or black polyethylene mulching to prevent early weed competition to pepper crop.

\Effect of some Weed Control Practices on Coriander (Coriandrum sativum L.) Productivity and their Associated Weeds

“…Stomp extra and Aemx being dinitroaniline, are known to be absorbed by germinating weed seedlings and inhibits cell division in meristematic tissue so that most of weeds die within few days of their emergence. These results are in agreement with obtained by Nagar et al (2009) Yadav et a.l (2015), Galal et al (2019) and Galal et al (2020). Savaliya et al (2017) reported that the highest weed control efficiency were registered under treatments of two hand weeding at 20 and 40 days after sowing and pendimethalin at 1.0 kg/ha as pre-emergence + quizalofop ethyl 0.04 kg/ha at 20 days after sowing 85.3 and 79.3%, respectively.…”

“…which recorded increase in seed yield which determined by 230.2, 222.3, 202.6 and 200.9% & 224.8, 216.0, 207.8 and 206.1 % , and increases in net income LE per feddan by 7050, 5130, 4350 and 5630, & 7600, 6560, 5775 and 7075, and highest gross income by 20850, 20130, 18350 and 18180, & 21400, 20560, 19775 and 19625, and increases in benefit/costs ratio to 1.51, 1.34, 1.31 and 1.45 & 1.55, 1.47, 1.41 and 1.56 in 2016/2017 and 2017/2018 than unweeded check respectively, meanwhile the benefit / costs ratio in unweeded check were minus than one in both seasons. These results are in agreement, Kushwaha et al (2002) Savaliya et al (2017) Yadav et al (2013, Gasti and Chakravorty (2019), Galal et al (2019) and Galal et al (2020). Note that the prices are approximate in the two seasons for costs and gross.…”

“…Gasti and Chakravorty (2019) found that pre-emergence application of pendimeathalin at 1.5 a.i kg / ha alone, supplemented with one hand weeding after 45 days after sowing or two hand weeding after 45 and 60 days after sowing gave the greatest plant height, number of branches per plant, yield per ha., net returns and B:C ratio in coriander. Savaliya et al (2017), Gasti and Chakravorty (2019), Galal et al (2019) and Galal et al (2020). c:Oil percentage and oil yield (l/fed.)…”

“…for pea andGalal et al (2020) for pepper.Table 8. Correlation between fresh weight of broad leaved, grassy weeds and total weeds with yield and yield components…”