Studies on the use of agricultural residues as an alternative to commercial substrates have become fundamental tominimising the risk of environmental contamination resulting from inadequate disposal, as well as reducing seedling production costs. This research involved an evaluation of growth variables and quality of cucumber seedlings produced in substrates with different compositions of agricultural waste with a view to providing substitutes for commercial substrate. The experiment was based on a completely randomised design, with six treatments and ten replicates. There were five treatments with increasing proportions of moinha/decreasing proportions of carbonized rice husk (0/40, 10/30, 20/20, 30/10 and 40/0%) and fixed proportions of coconut fibre (15%), eggshell (5%), pine bark (40%), and one commercial substrate treatment as the control (Bioplant®). The variables evaluated were: electrical conductivity of the substrate, plant height, stem diameter, number of leaves, Dickson quality index (DQI) and dry matter of roots and above ground parts. Results show that alternative substrates can replace commercial substrate without impairing the quality of cucumber seedlings. However, the substrate containing 40% of moinha, 0% of rice husk, 15% of coconut fibre, 5% of eggshell and 40% of pine bark resulted in the highest values for all evaluated variables and appears to be the most promising alternative substrate for the production of cucumber seedlings.

The objective of this study was to evaluate the growth variables of eggplants seedlings produced in substrates with different compositions in agricultural residues. The experiment was carried out in a completely randomized design, with five treatments and ten replicates, with the following treatments: T0= Bioplant commercial substrate (control); T1= 10% of moinha (dried residue of coffee beans) + 15% of coconut fiber + 5% of eggshell + 70% of commercial substrate; T2= 20% of moinha + 15% of coconut fiber + 5% of eggshell + 60% of commercial substrate; T3= 30% of moinha + 15% of coconut fiber + 5% of eggshell + 50% of commercial substrate; T4= 40% of moinha+ 15% of coconut fiber + 5% of eggshell + 40% of commercial substrate. The evaluated variables were electric conductivity of the substrate, number of leaves, plant height, stem diameter; and fresh and dry biomass of shoot, root, and of the whole plant. Growing doses of moinha provide increased electrical conductivity in substrate. The treatment groups containing increasing proportions of moinha in the substrate composition present the highest values of growth variables in relation to the commercial substrate. Except shoot, root and total dry biomass, the substrate with 10 and 20% of moinha have the highest values of analyzed variables in eggplant seedlings.

Efeito de diferentes proporções de moinha de café na composição de substratos alternativos para produção de mudas de pepino Effect of different proportions of coffee chaff on the composition of alternative substrates for producing cucumber seedlings

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Research related to the use of agricultural residues as alternatives to commercial substrates has become fundamental for reducing the production costs of coffee seedlings. The objective of this study was to evaluate the effect of residues of pepper (Piper nigrum) powder, coffee (Coffea) husk, coconut (Cocos nucifera) fiber and pine (Pinus) bark as alternative substrates in the development of coffee (Coffea canephora) seedlings in tubes. The experiment was carried out at the Demuner Seedling Nursery, in the municipality of São Roque do Canaã, Espírito Santo, Brazil. The experimental design was completely randomized, with six treatments: T0- Bioplant® commercial substrate (control); and from T1 to T5, increasing proportions (%) of pepper powder and decreasing coconut fiber and pine bark (0/20/50, 10/15/45, 20/10/40, 30/5/35 and 40/0/30) and fixed proportions of coffee husk (30%). At 120 days after staking, we evaluated the plant height, number of leaves, stem diameter, shoot dry mass and root dry mass. Any of the substrates containing different proportions of agricultural residues can be used as an alternative to the commercial substrate in the production of Conilon coffee seedlings since most of the growth variables evaluated did not differ from the control. Due to the high availability of pepper powder in the region, we recommended the substrate with 40% pepper powder, 30% coffee husk and 30% pine bark.