Assessment of weed dynamics under different sowing dates and weed management practices on the irrigated field pea (Pisum sativum L.)

Introduction

Pulses are 2 nd important cultivated crop after cereals. Variety of pulse crops grown in India and the entire world. In India, Field pea (Pisum sativum L.) is the 3 rd most important rabi pulse after chickpea and lentil. It belongs to the family Fabaceae and subfamily Papilionoideae. Field pea is a good source of protein and primarily used for human consumption and also used as livestock feed. It contains 15-35% protein, 20-50% starch, 4-10% sugar, 2-4% minerals and 0.6-1.5% fat (Makasheva, 1983) [5] . In India, the cultivated area of field pea is about 0.76 million ha with an annual production of about 1.04 million tonnes and estimated yield of field pea is 13.18 q ha -1 [Anonymous. 2021. (a)] [1] . In Chhattisgarh, the field pea is mostly grown in rabi season. Cultivated area of field pea in Chhattishgarh is 13690 ha with production of 5354 metric ton. There are many constraints that are responsible for losses of field pea yield but the biggest threat is weed competition. In India, agriculture fields are generally infested by broad-leaved and grassy weeds in wide spectrum which competing with the crop plants for light, nutrients, water and alleopathic effect of harboring harmful pests (Dittmar and Boyd 2015) [2] . The critical period is up to 60 DAS for crop weed competition in pea. Weed competition reduces the quantity of pods and seeds pod -1 , which causes a significant production loss of up to 65.8% under unweeded conditions (Mishra, 2006) [7] . There are some herbicides available viz., Metribuzin, Imazethapyr + Imazamox (pre-mix) etc and also manual hand weeding are able to check the emergence and growth of grasses and broad-leaved weeds of pea. It is imperative to find out optimum date of sowing and effective weed management practices for better growth and yield of field pea. The present investigation was carried out to evaluate the Effect of date of sowing and weed management practices on the performance of irrigated field pea.

Materials and Methods

A field experiment entitled the effect of date of sowing and weed management practices on the performance of irrigated field pea (Pisum sativum L.) was conducted at the Instructional Farm, DKS College of Agriculture and Research Station in Bhatapara, Chhattishgarh, during Rabi season of 2023-24. The experimental field was neutral in pH and clayey texture soil. The range of mean maximum and minimum temperatures 24.8 to 38.9 ºC and 10.1 to 23.6 ºC during the crop growth and development period was respectively. The range of the relative humidity 63.7-90.3%, bright sunshine 1.8 to 9.2 hrs day -1 , wind speed 0.1 to 4.5 km hr -1 and daily evaporation 13.8 to 47.3 mm was respectively. The experiment conducted in a Split Plot Design with 15 treatment combinations comprising of three different sowing dates viz., (D1: 01 November, D2: 20 November and D3: 10 December) and five weed management practices viz., (W1: Weedy check, W2: Weed-free, W3: Two hand weeding at 20 and 40 DAS, W4: Metribuzin 250 g a.i. ha -1 as PoE and W5: Imazethapyr + Imazamox (pre-mix) 70 g a.i. ha -1 as PoE) were replicated thrice. Weed identification, relative density, weed density, dry matter accumulations, yield attributes, productivity, cost of cultivation, gross returns, net returns and B: C ratio were recorded or computed after the harvested of the crop. The data obtained on various observations for each treatment were subject to 'Analysis of variance' as recommended by R. Rangaswamy (2005) [9] . Weed index, weed control efficiency and weed dominance were worked out using the following formulas:

Result and Discussion

Weed identification

Each kind of weed has an own characteristic and it was identified at different growth stages viz. 20, 40, 60 and 80 DAS. The experiment field was heavily infested with different weed flora. The predominant grasses were Echinochloa colona and Cynodon dactylon, sedge was Cyperus rotundus (L.) Whereas, the Anagallis arvensis was the pre dominant broad leaved weed followed by Trifolium repens, Convolvulus arvensis, Parthenium hysterophorus and Euphorbia hirta. It was discovered that the majority of the weeds seen in the experimental field resembled those described by Punia et al. (2017) [8] and Kumar et al. (2023) [4] . The recorded data was presented in Table 1. [10] , Jilani et al. (2016) [3] and Kumar et al.

(2023) [4] . The recorded data was presented in Table 2.

The study assessed on different growth stages at 20, 40, 60 and 80 DAS and recorded that the weed dry matter effectively reduced under 20 November (D2) and two hand weeding at 20 and 40 DAS (W3) and recorded maximum under 10 December (D3) sowing date and weedy check (W1). However, all the weed management treatments significantly reduced the weed dry matter accumulation compared to weedy check. These results are similar to findings of Mathukia et al. (2015) [6] , Punia et al. (2017) [8] and Kumar et al. (2023) [4] . The recorded data was presented in Table 3.

The weed index was influenced by different date of sowing and weed management practices. The lowest weed index with highest seed yield was recorded under sowing date 01 November; D1 (19.63%) and two hand weeding at 20 and 40 DAS; W3 (11.17%) Similar findings have been reported by Verma et al. (2022) [11] and Kumar et al. (2023) [4] . The recorded data was presented in Table 4. [11] and Kumar et al. (2023) [4] . The recorded data was presented in Table 4.

It is evident from the data that crop sown on 20 November (D2) and two hand weeding at 20 and 40 DAS (W3) were recorded the lowest weed dominance of major no. of weed species and maximum on late sowing and weedy check.

Anagallius arvensis had the highest dominance all over the field in rabi season. These findings are similar with the findings of Punia et al. (2017) [8] and Kumar et al. (2023) [4] . The recorded data was presented in Table 5.

Conclusion

From the present investigation it is concluded that the sowing date 20 November (D2) and weed free (W2) were found very effective to reduce the weed density and weed dry matter accumulation. Therefore two hand weeding at 20 and 40 DAS (W3) followed by is recommended for pea weed management and less chemical use. The sowing date 20 November (D2) and two hand weeding at 20 and 40 DAS (W3) had higher weed control efficiency (%) with lower weed index (%) while weedy check (W1) had 0% control efficiency with higher weed index. The highest weed dominance (%) of Anagallis arvensis was recorded treatment under sowing date 10 December (D3) and weedy check (W1).

References

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