Effects of shade on arbuscular mycorrhizal colonization and growth of crops and tree seedlings in Central India
The study was conducted to investigate the effects of different light intensities (25, 50, 67, and 100% of full sun [open]) on arbuscular mycorrhizal (AM) colonization and growth of two intercrops (a rainy season crop, Phaseolus mungo Roxb. var. PU-35 and a winter crop, Triticum aestivum L. var. WH-147) and seedlings of two multipurpose tree species (Eucalyptus tereticornis Sm. [Clone C-7, ITC, Bhadrachalam] and Albizia procera Benth.) of Central India. The results showed that various plant growth parameters viz., shoot length, dry weight and phosphorus (P) uptake were adversely affected by low light intensity. Inoculations with AM fungi (Acaulospora scrobiculata Trappe, Glomus intraradix Schenck & Smith and an unidentified Glomus species) increased the plant growth on account of all measured parameters under tested light conditions. Mycorrhizal efficiency of different AM fungi varied in narrow range. AM inoculants were more efficient at higher light intensity in above mentioned plant species, except wheat. Data on colonization of P. mungo, T. aestivum, E. tereticornis and A. procera showed that formation of arbuscules, vesicles and sporocarp was delayed by lower light intensity. Colonization index of host roots and spore counts increased with increase in light intensity during successive months after inoculation. Data on effect of light regimes on microclimate of net house showed that lux meter reading decreased as per grades of shading nets used during both rainy and winter seasons. With increase in light intensity, ambient temperature, soil surface temperature and sub surface temperature at 15 cm depth increased, except that the ambient and soil surface temperature in control (open) were slightly lower than net house observations during January and February. Value of ambient temperature varied in narrow range, with in treatments as compared to soil surface and sub soil surface temperature at 15 cm depth. Soil surface temperature at 25% of full sunlight was less than respective control values by 2–11°C and sub soil temperature at 15 cm depth was less by 4–12°C. The values of different microclimate parameters varied in narrower range during winter season as compared to rainy season. While ranking the importance of two factors studied—light and AM fungi—for their effect on the growth and P uptake by different plant species, inoculations with AM fungi came in the first place (explained 50–82% variation) and light substantially increased the values of R 2 in stepwise regression analysis (forward selection). The results suggest that AM inoculation may enhance the growth and P uptake of intercrops under tree shade and the tree canopy management is likely to increase the efficiency of AM inoculants in agroforestry systems. Use of excessive shading (25% of full sun or more) in nurseries may be avoided and PAR (photosynthetically active radiation) lamps may be used to increase growth and colonization index of tree seedlings. 
Development of soil salinity during germination and early seedling growth and its effect on several crops
To study the development of soil salinity during germination and early seedling growth experiments were conducted in buckets filled with 20-cm deep soil. The experiments consisted of a control and three saline treatments with initial chloride concentrations of 30, 60 and 90 meq/l. The experiments were carried out on sandy loam, loamy sand and sand. In each soil wheat and sunflower were grown together and were followed by sorghum and safflower together. The crops were irrigated 0, 10, 17 and 24 days after sowing. Moreover an experiment was done in glass cylinders with constant chloride concentrations.
During germination and early seedling growth, the salt concentration of the soil water increased strongly due to capillary salt transport to the top layer and due to the decrease in water content during the irrigation interval.
Increasing salt concentration delays germination but after ten days a high germination percentage is attained for salt tolerant crops like safflower, sorghum, sunflower and wheat. During early seedling growth these crops appear to be less tolerant than during germination and later growth. 
Bioherbicidal effects of tree extracts on seed germination and growth of crops and weeds.
Laboratory based studies were conducted to investigate the allelopathic potential of aqueous extracts (150 g/litre each) of Prosopis juliflora and Eucalyptus camaldulensis leaves and Acacia nilotica bark. The germination percentage, seedling length (mm) and biomass yield per plant of Ipomoea sp., Asphodelus tenuifolius, Brassica campestris and Triticum aestivum were significantly affected by the extracts. Eucalyptus camaldulensis and Acacia nilotica had a stimulatory effect on germination percentage of Asphodelus tenuifolius, while Prosopis juliflora and Eucalyptus camaldulensis had inhibitory effect on Brassica campestris. All extracts had inhibitory effects on seedling length of Triticum aestivum and Brassica campestris. Treatment means indicated that Prosopis juliflora and Eucalyptus camaldulensis are more allelopathic than Acacia nilotica. The effect of Acacia nilotica on the test species was statistically comparable with the control, exhibiting its non-inhibitory role in the test species. Species means indicated that Ipomoea sp. and Triticum aestivum were less negatively affected than Brassica campestris and Asphodelus tenuifolius. Hence, Prosopis juliflora and Eucalyptus camaldulensis can be exploited as bioherbicides for sustainable weed management. 
Effect of Processed Feather Waste as Mulch on Crop Growth and Soil Fertilization
Management of waste feathers in Nigeria is of public health concern due to large quantities generated daily from poultry industries and slow degradation in soil. Information on processing waste feathers for enhancing crop growth has not been well documented, particularly in Nigeria. This study assessed the effect of processed waste feathers on crop growth and soil fertilization in order to provide a cheap and sustainable source of organic fertilizer for use.
The study design was experimental and laboratory based, using maize as test crop. Waste chicken feathers were washed, air-dried, ground into bits, and analyzed for nitrogen, phosphorus and potassium contents. Eighty grams feather-bits were mixed with 27 g of glycerol plasticiser at 65°C to obtain a paste and then pressed for ten minutes into flattened organic mulch. Eight 14 cm-diameter pots of 1.5 liters capacity were obtained and divided into two groups (A and B) of four replicates each in a completely randomized design. Maize seeds were planted in 1 kg sieved soil in the pots. Surfaces of the soil in the experimental group B was covered with feather mulch while control group A was without mulch. All pots were sprinkled with water daily to water holding capacity. Length of leaves and shoots of crop were measured at intervals for 28 days using flexible measuring tape. Data were analysed using descriptive statistics and student t-test. 
Density and Cultivar Effects on the Biomass and Crop Growth Rate of Upland Rice in Uyo Southeastern Nigeria
Aims: To evaluate population densities and cultivars on the biomass and crop growth rate (CGR) of upland rice and their correlation with grain yield.
Study Design: A Factorial on randomized complete block design.
Place and Duration of Study: The Teaching and Research Farm of the Faculty of Agriculture, University of Uyo, between May 12, 2009 and September 30, 2010.
Methodology: Six sowing densities; 1,600,000, 1,066,666, 800,000, 640,000, 533,333, and 2,054,435 plants ha-1 were combined with five cultivars of rice; FAROs 43, 46, 55, 56 and a local cultivar – Otokongtian. Treatment combinations were replicated three times. Destructive samples were collected at 3, 6, 9, 12, and 15 weeks after sowing (WAS), oven-dried at 80°C to constant weight and the biomass and CGR determined. Data were analyzed with Genstat Discovery Edition 4 and means compared by Fisher’s protected least significant difference at 5% probability.
Results: Rice biomass for 2,054,435 and 1,600,000 densities increased significantly (8.77-12.55 and 7.08-11.44 g m-2) at 3 WAS in 2009 and 2010 respectively (P=.05). Biomass increase was highest at 15 WAS across densities and cultivars in both years. FARO 46 produced the highest significant biomass in both years during the period but was replaced by Otokongtian at 15 WAS. At 3-6 WAS, 2,054,435 produced the highest significant CGR in both years (5.83 and 5.193 g m-2 day-1 for 2009 and 2010 respectively), while FARO 43 had the highest CGR during the period. Higher densities produced higher CGR. The CGR continued to increase across densities and cultivars up to 9-12 WAS and began to decline at 12-15 WAS. There was a positive correlation between rice biomass, CGR and grain yield.
Conclusion: Higher sowing densities produced higher rice biomass and CGR which correlated positively with grain yield. 
 Shukla, A., Kumar, A., Jha, A., Chaturvedi, O.P., Prasad, R. and Gupta, A., 2009. Effects of shade on arbuscular mycorrhizal colonization and growth of crops and tree seedlings in Central India. Agroforestry Systems, 76(1), pp.95-109.
 Van Hoorn, J.W., 1991. Development of soil salinity during germination and early seedling growth and its effect on several crops. Agricultural Water Management, 20(1), pp.17-28.
 Khan, M.A., Marwat, K.B., Gul, H. and Zahid, H., 2005. Bioherbicidal effects of tree extracts on seed germination and growth of crops and weeds. Pakistan Journal of Weed Science Research, 11(3/4), pp.179-184.
 Okareh, O. T., Awe, A. O. and Sridhar, M. K. C. (2015) “Effect of Processed Feather Waste as Mulch on Crop Growth and Soil Fertilization”, Journal of Agriculture and Ecology Research International, 4(1), pp. 25-35. doi: 10.9734/JAERI/2015/17248.
 Aderi, O. S. (2015) “Density and Cultivar Effects on the Biomass and Crop Growth Rate of Upland Rice in Uyo Southeastern Nigeria”, Journal of Experimental Agriculture International, 10(3), pp. 1-11. doi: 10.9734/AJEA/2016/20597.