1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)

Permanent URI for this communityhttp://localhost:4000/handle/123456789/1

Browse

Subject: search.filters.subject.Crop weed competition

Search Results

Now showing 1 - 6 of 6
  • No Thumbnail Available
    Item
    Effect of time of sowing and weed management on the performance of dry sown rainfed rice
    (Department of Agronomy, College of Agriculture, Vellayani, 1993) Jacob John; Thomas Alexander, V
    An experiment was conducted at the College of Agriculture, Vellayani during the first crop season of 1992 to study the effect of time of sowing and weed management on the performance of dry sown rainfed rice using Onam variety. Split plot experiment in randomised block design with time of sowing as major treatments and weed management as minor treatments was adopted and the treatments replicated thrice. May 16, May 23 and May 30 were the first, second the third dates of sowing respectively. The weed management treatments included combination of butachlor with 2, 4-D, butachlor with hand weeding, hand weeding twice 20 and 40 DAS, complete weed free and un weeded control. Sowing on May 23 resulted in greater plant height, panicle weight, grain and straw yield, nutrient uptake, grain protein and lesser uptake of phosphorus and potash by weeds when compared to May 16 and May 30. The second best sowing date was May 16. When compared to un weeded control, hand weeding twice, combination of butachlor with hand weeding and butchlor with 2, 4-D gave higher plant height, tiller number, productive tiller number, panicle weight, thousand grain weight, grain yield, straw yield, nutrient uptake and grain protein out of which hand weeding was the best. Hand weeding also resulted in the lowest weed population, weed dry weight, nutrient uptake by weeds, weed index and the highest weed control efficiency. Initially, butachlor alone was ineffective in reducing weed population and its dry weight. However, the combination of butachlor with 2,4-D and butachlor with hand weeding was effective in later stages. The combination of butachlor with hand weeding resulted in higher weed control efficiency than butachlor with 2,4-D. The rice grains contained no applied weedicide residues. Hand weeding, combination of butachlor with hand weeding and butachlor with 2,4-D resulted in greater profit and benefit – cost ratio than un weeded control. However, the highest profit was obtained with hand weeding twice.
  • No Thumbnail Available
    Item
    Weed management in sole and intercropped coconut gardens
    (Department of Agronomy, College of Horticulture, Vellanikkara, 1990) Savithri, K E; Sreedharan, C
    Field experiments were conducted during the period from 1986 to 1989 at the Agricultural Research Station, Mannuthy, Thrissur to develop weed management practices for sole and intercropped coconut gardens. There were three fields trials. In trial - I the treatments comprised of three manual methods (digging once, digging twice and sickle weeding), six chemical methods (paraquat three sprays, glyphosate 0.4 kg ha-1, glyphosate 0.8 kg ha-1 dalapan followed by paraquat, paraquat + diuron and paraquat followed by glyphosate), two combinations of manual and chemical methods (2,4-D + diuron immediately after sickle weeding and glyphosate followed by digging) were compared with weed free and unweeded control in underplanted coconut garden. In trial - II, the treatments comprised of two manual methods (spade weeding and sickle weeding ), one cultural method (growing cowpea as an intercrop) two cultural + chemical methods (cowpea followed by paraquat or glyphosate), three pre-emergence herbicides + post-emergence herbicide (diuron followed by paraquat, oxyfluorfen followed by paraquat and atrazine followed by paraquat ) were compared with weed free and unweeded control in coconut+ banana cropping system. Unweeded control in coconut banana cropping system was compared with that in sole crop of coconut . In trial III, the treatments tried in coconut+banana cropping system were eveluated in sole crop of banana and there were thirteen treatments . All these three trials were laid out in Randomised Block Design and replicated thrice.
  • No Thumbnail Available
    Item
    Sequential and combined application of herbicides in dry sown rice
    (Department of Agronomy, College of Horticulture, Vellanikkara, 1989) Jolly Chacko Palaikudy; Abraham, C T
    Field experiments were conducted during Virippu (1st crop season) of 1967 ie. from June to September at Agricultural Research Station, Mannuthy under the Kerala Agricultural University, Vellanikkara, Kerala with the objective of evaluating the efficiency of repeated application of pre-emergence herbicides asa well as combined application of pre emergence and post emergence at early post emergence stage of rice so as to develop a cheaper and efficient herbicide sequence for season long weed controlin dry sown rice. Fifteen treatments were compared with farmers practice of hand weeding, unweeded control and post emergence application of propanil alone. The experiment was carried out in R,B,D with three replications.
  • No Thumbnail Available
    Item
    Studies on the critical periods of weed infestation and effect of weed growth on yield and quality of a short duration rice
    (Department of Agronomy, College of Agriculture, Vellayani, 1978) Abraham Varughese; Madhavan Nair, K P
    An experiment was conducted at the Instructional Farm of the College of Agriculture, Vellayani, Kerala Agriculture University during the second crop season, 1976-77 to study the critical periods of used infestation and effect of weed growth on the yield and quality of a duration rice ver. Triveni Simple randomised block design was adopted with 17 treatments. Band weeding was done to keep weed free conditions of 10,20 and 30 day intervals upto 60th day and for 1-60 days after transplanting. The above weed free periods with one unweeded control formed the 17 treatments.
  • No Thumbnail Available
    Item
    Low cost technology for weed management in rice-1 influence of plant population on the comparative ability of short duration rice on weed communities
    (Department of Agronomy, College of Agriculture, Vellayani, 1989) Bindy, T S; Madavan Nair, K P
    An experiment was conducted at the college of Agriculture, Vellayani during the Virippu (first crop) season of 1987, to evolve a suitable low cost technology for weed management for short duration transplanted rice cv. Thriveni in split plot design with 16 treatments and 3replications. Monocot weeds predominated throughout the crop growth. Hand weeding twice at 20 and 40 DAT controlled monocot, dicot and total weed population and decreased weed dry matter production. Closer spacing of 10x10 cm and planting 4 seedlings/hill also helped to suppress monocot and dicot wee population and weed dry matter production. Weed control efficiency was highest for hand weeding twice with a spacing of 10x10cm and planting 4 seedlings /hill. Completely weed-free condition resulted in highest tiller production, dry matter production of the crop and productive tillers/m2, followed by hand weeding twice with a spacing of 10x10cm and planting 4 seedlings/hill also resulted in increased tillers/m2, crop dry matter production and productive tillers/m2. Completely weed-free condition and planting 4 seedlings/hill resulted in high leaf area index. Other yield attributes like number of spike lets/panicle, filled grain/panicle, panicle weight and thousand grain weight were also high for completely weed-free condition with a wider spacing of 15x10cm and planting 2seedlings/hill. Grain and straw yields were highest for completely weed –free condition followed by hand weeding twice. Wider spacing of 15x10cm and planting 2 seedlings/hill increased grain yield, while closer spacing of 10x10cm and planting 4 seedlings/hill increased straw yield. Hand weeding twice recorded highest weed index. Nutrient up take by weeds was lowest in weeded treatments, which in turn enhanced the crop uptake. Closer spacing of 10x10cm, and planting 4 seedlings/hill also reduced weed nutrient uptake and increased crop nutrient uptake. Hand weeding twice with a wider spacing of 15x10cm and planting 2seedlings/hill gave the highest net income and cost- benefit ratio
  • No Thumbnail Available
    Item
    Bio efficacy of post emergence micro herbicides in transplanted rice (Oryza sativa L)
    (Department of agronomy, College of agriculture, Vellayani, 2013) Rathod Nilesh Dayaram; Elizabeth K Syriac