The Influence of Plastic Mulching Materials and Sowing Dates on the Yield and Yield Components of Pea (Pisum sativum L.)

The use of plastic mulches affects the microclimate in the vicinity of the plant by modifying the radiation on the soil surface and reduce the loss of water. Pea is more nutritious and 2 food source after cereals at Pakistan, but due to lake of proper management, yield is still not up to mark as compare to developed world. To reduce this problem, a field experiment was conducted to investigate the effect of mulching material and sowing dates on the yield of Pea. The study consisted of three different mulching materials (Polythene Black, Polythene Blue and Polythene Brown) with three different sowing dates (1, 15 and 30 October) arranged in a Randomized Complete Block Design with three replications. The results showed that different sowing dates and mulching materials had significant effect on the yield parameters of Pea. Regarding sowing dates, maximum days to pod formation (8.08 days), pods plant (21.25), Pod weight (18.84 g) and pod yield (4.39 tons ha) were noted in pea sown on October 1. Whereas, minimum data of days to pod formation (3.08 days), pod plant (15.34), pod weight (13.17 g) and pod yields (2.69tons ha) were recorded in pea sown on October 30. In case of mulching types maximum number of pods plant (19.00), pod length (6.89 cm), seeds pod (7.78), pod weight (17.34 g) and pod yield (3.69 tons ha) were observed in pea mulched with Polythene Black, while minimum pods plant, pod length, seeds pod, pod weight and pod yield were found in control. The study suggested that pea should be sown on October 1 while mulched with www.scholink.org/ojs/index.php/ra Research in Agriculture Vol. 3, No. 2, 2018 51 Published by SCHOLINK INC. Polythene Black to produce maximum yield and production in agro environment of district Peshawar.

Published by SCHOLINK INC. after the harvest. Most of the farmer burnt the remaining plastic films that is left on the field, which produced harmful gases and pollute the environment (Scarascia-Mugnozza et al., 2006). The solution for the disposal of plastic mulch could be used the biodegradable plastic that are mostly made of polysaccharides, starch and cellulose. The biodegradable plastic film mulch when placed in contact with water and microorganism been decomposed by the bacteria and fungi in the soil (Scarascia-Mugnozza et al., 2004. Keeping in view the importance of Pea in agriculture and issues regarding sowing times and mulching materials on the seedling germination and yield. Therefore, the main objectives of the study were: 1) to find the suitable sowing date, 2) to evaluate the effect of mulching material on yield of pea.

Experimental Design
A research project entitled "Response of Pea to different sowing dates and mulching materials" was carried out at Horticulture Research Farm, The University of Agriculture Peshawar during 2014-2015.
The experiment was laid out in Randomized Complete Block (RCB) Design with three replications.
There were two factors. Factor A consist of different sowing dates, i.e., October 1 st , October 15 th and October 30 th . While Factor B consist of different plastic mulching treatments that were control, Polythene Black, Polythene Blue and Polythene Brown. Basic dose of N: P: K was applied @ (40, 50, 150 kg ha −1 ). Phosphorous and Potassium were applied before sowing while nitrogen was applied in split doses, i.e., half before sowing and half after one month. The numbers of pods were counted on middle rows in each treatment and average pods/plants were calculated.

Pod length (cm)
Fifty pods were randomly selected in each treatment and then the length was measured in centimeters and average was calculated.
Total seeds pod −1 Fifty pods were randomly selected in each treatment and the number of total seeds was recorded and average was calculated.
Pod weight plot −1 (g) Weight of 100 seeds in each treatment was taken and average weight per 100 was calculated.

Pod yield (tons ha −1 )
Seed yield per plot was taken and the seed yield per hectare was calculated from the seed yield plot −1 .

Statistical Analysis
The data were analyzed individually for each parameter by using statistical software Statistix 8.1, through Randomized Complete Block (RCB) design with two factorial arrangement. Means were compared by using Least Significant Difference (LSD) test at 0.05 level of probability (Steel & Torrie, 1980).

Days to Pod Formation
Sowing dates and mulching materials has significantly affected days to pod formation ( Table 2). The data analysis of variance shows that mulching and sowing dates had significantly influenced the days to pod formation of pea cv. Climax, while its interaction had non-significant effect.
Regarding mulching techniques maximum days to pod formation (6.34 d) were recorded in control followed by ( on October 30 th . The early pod formation in pea sown may be due at the end of October was due to favorable climatic temperature. These results are in line with previous results of Baloch (1994) who investigate that, pea grow well in winter due to the availability of sufficient moisture, while hot and dry climatic conditions discourage its growth. Warm climate interferes to seed set and winter with the quality of pods formation.

Number of Pods Plant -1
Sowing dates and mulching materials had significant (p<0.05) effects on number of pod plant −1 ( Table 3).
The data analysis of variance shows that mulching and sowing dates had significantly influenced the number of pods plant −1 of pea cv. Climax while its interaction had non-significant effects.

Total Seeds Pod -1
The tabulated data (Table 5) of different sowing dates and mulching materials had significant effects on pea total seeds pod −1 . The data analysis of variance shows that mulching and sowing dates had significantly influenced the total seeds pod −1 of pea cv. Climax while its interaction had non-significant observed.
In mulching techniques, the maximum seeds pod −1 (7.78) was reported in pea with PE Black mulched followed by (7.34) to PE Blue, whereas the minimum seeds pod −1 (6.23) were found in pea for control.
PE Black mulch give positive response to the number of seeds pod −1 may be due to maximum nutrients in the soil, maximum plant height, high length of pods and sufficient moisture content in soil. This resultant value has conformity with Lamont (1999) who founded that maximum number of seeds pods −1 are recorded for with PE Black mulch as compare to other mulching techniques.
Similarly, for sowing dates highest total seeds pod −1 (8.92) were reported in pea sown on October 30 th and then (6.84) October 15 th , while the lowest total seeds pod -1 (5.50) were noticed in pea sown on October 1 st . The highest number of seeds pod −1 in pea sowed on October 30 th may be due to the favorable temperature and day length. According to Duke (1981) who suggested that pea vegetative growth is tolerate to maximum weather, but in smaller stage flower produce. So, the seeds and pods production were healthier due to high temperature the quantity and quality are inhibited. So therefore, early sowing is stronger to most favorable temperature with long pods resultant as maximum number of seeds pod −1 .

Pod Yield (Tons ha -1 )
Sowing dates and mulching materials has significantly affected pod yield (tons ha −1 ). The data analysis of variance shows that mulching materials and sowing dates had significantly influenced the pod yield (tons ha −1 ) of pea cv. Climax while its interaction had non-significant effects (Table 7).
Pertaining mulching techniques, the highestpod yield (3.69 tons ha −1 ) was noted in pea mulched with PE Black followed by peas mulched with PE Blue (3.62 tons ha −1 ), whereas minimum pod yield was observed for control (3.09 tons ha −1 ). The more pod yield in pea mulched with PE Black may be due to maximum soil nutrients and soil moisture availability as PE Black reserved the soil nutrients by damaging weed plants and retard its growth due to which the nutrients available in soil and weed plants became reserved. PE Black mulch in early stage are good for better yields and make crops free from weeds (Dittmar & McRae, 2012).
In the case of sowing dates, the highest pod yield (4.39 tons ha −1 ) was observed in pea sown on October  LSD α 0.05 for sowing dates=0.0792.

Conclusion
The results of the present study concluded that the early sowing of pea showed highest number of pods plant −1 , pod weight and pod yield. In the case of mulches, PE Black mulching showed lowest days to pod formation, number of pods plant −1 , pod length, pod weight, pod yield and seeds pod −1 in pea. The early 1 st week of October as compared to 15 th and 30 th showed better performance in pea. PE Black mulching technique showed better performance in pea as compared to PE Blue and Brown mulches.