The experiment was carried out during Robi season of 2017-2018 in the net house of Soil Science Division, BARI, Joydebpur, Gazipur. Seedlings of chilli BARI Morich-2 and Onion BARI Piaj-4 were collected from Regional Spices Research Centre, BARI, Gazipur. The silted (sandy clay loam) soils were collected from the bank of Turag River at Kodda, Gazipur mixed with cowdung at 5:1 ratio and was used as the potting media. Each pot (28 cm in diameter and 23 cm in height) was filled with approximately 8-kg soil leaving upper 3 inches of pot was vacant to facilitate watering. The pH of cowdung was 6.7 and the nutrient contents were: organic matter 14.1%, N 0.8%, P 1.26%, K 0.88%, Ca 1.55%, Mg 0.82%, S 0.62%, Fe 0.25% and Mn 0.112%. The physical and chemical properties of the soil are presented in Table 1. The soil contained 12 AM (100-1 g soil) spores of indigenous mixed AM fungal species and each gram of soil contain a population of rhizobium, azotobacter and phosphate solubilizing bacteria (PSB) was 3.0 ´ 103, 5.0 ´ 103 and 3.8 ´ 103, respectively. The experiment was conducted under an unsterilized soil condition.
Soil pH was measured by a combined glass calomel electrode (Jackson, 1958). Organic carbon was determined by the Wet Oxidation Method (Walkley and Black, 1934). Total N was determined by a modified Kjeldahl method (Jackson, 1962). Calcium, K and Mg were determined by NH4OAc extraction method (Black, 1965). Copper, Fe, Mn and Zn were determined by DTPA extraction followed by AAS reading. Boron was determined by CaCl2 extraction method. Phosphorus was determined by Modified Olsen method (Neutral + Calcareous soils) according to Olsen et al. (1954). Sulphur was determined by CaH4(PO4)2.H2O extraction followed by turbidimetric turbidity method with BaCl2. Chemical fertilizers @ 100 kg N ha-1 from urea, 55 kg P ha-1 from TSP, 75 kg K ha-1 from MoP, 22 kg S ha-1 from gypsum, 5 kg Zn ha-1 from ZnSO4 for onion and 110 kg N ha-1 from urea, 45 kg P ha-1 from TSP, 75 kg K ha-1 from MoP, 20 kg S ha-1 from gypsum, 5 kg Zn ha-1 from ZnSO4 .7H2O for chilli were applied (BARC, 2012). All other fertilizers except urea-N were applied as basal during final land preparation and urea-N was applied at three equal splits. Healthy seedlings of chilli (BARI morich-2) and onion (BARI piaj-4) were collected from Regional Spices Research Centre, BARI, Joydebpur, Gazipur. After preparing the seedlings, 5 seedlings were transplanted each pot. Chilli seedlings were transplanted on 6th December 2017 and onion seedlings on 10th January 2018.
Three plants of chilli from each pot were harvested after 45 days after transplanting for recording some growth parameter like plant height, number of branch per plant, number of leaf per plant, shoot weight and root weight. Chilli was harvested at several times. The first harvest was done on 16th January 2018. Different parameters like a number of fruit plant-1, fruit length, fruit diameter, fruit yield per pot-1 were measured. In the case of onion, harvesting was done on 16th April 2018. Some parameters like plant height, individual bulb weight, bulb length, bulb diameter and bulb yield pot-1 were recorded. Data were statistically analyzed using Analysis of Variance (ANOVA) following CropStat package while they all pair comparisons were done by Statistix 10.