Australian Journal of Agricultural Engineering
Southern Cross Publisher©2009

Gas exchange activities and relative water content at different fruit growth and developmental stages of ON and OFF cultivated pistachio trees

Abdoreza Sajjadinia, Ahmad Ershadi, Hossein Hokmabadi, Mehdi Khayyat, and Mansour Gholami


The present research was carried out to study gas exchange activities at different stages of fruit growth and development in OFF and ON pistachio cultivars including Ohadi, Kalleh-Ghochi, Akbari, Ahmad-Aghaii, Rezaii Zoudras and Haratii. Thus, different off and on shoots were chose at different stages of fruit growth and development and also postharvest stage as followed: 1- beginning of endocarp growth; 2- pith hardening; 3- beginning of endosperm rapid growth; 4- end of embryo development; 5- ripening and harvesting times and 6- post harvest. Data indicated that gas exchange activities and relative water content significantly affected by cultivar, fruit growth and development stages and ON and OFF bearing statuses. The highest amount of photosynthetic activity was shown by Rezaii Zoudras followed by Akbari, Ohadi, Ahmad-Aghaii, Kalleh-Ghochi and Haratii, respectively. The highest and lowest photosynthetic (Pn) and transpiration (E) rates were resulted from 'Rezaii Zoudras' and 'Haratii', respectively. The highest rates of stomatal conductance (gs) and relative water content (RWC) were obtained by 'Ohadi', and 'Ohadi' and 'Kalleh-Ghochi', respectively. Data showed the highest and lowest Pn at first (T1) and fifth (T5) stages of fruit growth and development. The highest and lowest rates of E were obtained at second and third stages and fifth stage, respectively. Our results illuminated that gas exchange activity studies are the main way choosing the best cultivar for a special condition.

Pages 1-6 PDF Full Text
Economic analysis of farm hazards associated with the use of agrochemicals on agricultural farms

Tekwa, I.J., Ambali, O.Y. and Gabdo, B.H


This paper assessed the economic implications of farm hazards associated with the use of agrochemicals on some farms in four locations namely; Digil, Gella, Lokuwa and Shuware in Mubi environment between May and December, 2008. Relevant data on socio-economic background of the farmers and the agrochemical farm hazards were sampled using structured questionnaire (80 copies) administered among the target farmers. 72 copies were filled, returned and analyzed for this study. The test-re-test method of data validation was employed. Data collected was also compared using descriptive statistics. The result indicated that the sampled farmers were predominantly middle aged (40-50 years) with farming experiences of mostly 20 years. Of the three principal farm hazards management types (weeds, insects and soil fertility) assessed, insecticides application was accounted as the highest (70%) source of farm hazard, especially in Gella. Simple cost analysis of farmers’ health hazard, crop damage and animal health hazard recorded an estimated loss of $1,007.75; $32,333.46 and $7,310.09 respectively. This high loss was notably attributed to poor skills of the farmers. It is therefore recommended that, awareness campaigns and mass trainings on the use, handling and application of agrochemicals should be encouraged in order to achieve effective and safe use of agrochemicals in the study area.

Pages 7-13 PDF Full Text
Effect of Herbicides, seed dressing chemicals and spray regimes on germination, insect infestation and yield of Cowpea (Vigna unguiculata (L) Walp)

Tekwa IJ, Ijabula ST and  Maijama’aNP


A field experiment was conducted in Samaru-Zaria located between latitudes11010’ and 10054’N and longitudes 07038’ and 07044’E within the guinea Savanna zone of North central Nigeria. The effect of seed treatment chemicals (Apron Star® 24WP, 20% w/w Thiamethoxoams, 20% w/w Metalaxyl-M and 20% w/w Difeno- conazole) and four spray regimes (5 days, 7 days, 10 days and 14 days after sowing) on the germination, insect infestation and yield of cowpea (Vigna unguiculata (L) Walp) (SAMPEA-7) were investigated during the 2006/2007 rainy season. The experiment comprised of five treatments replicated four times in a randomized complete block design (RCBD). The result obtained showed that seeds dressed with Apron Star® recorded higher germination counts (35 seedlings) compared to the undressed seeds, which had the least estimates (26.75 seedlings) and lower yields (366.7kg/ha). The SAMPEA-7 seeds dressed and protected with Cypermethrin and Dimethoate for the control of field insect pests gave significant (p<0.05) grain yield per ha under 7 days (1387.50kg/ha) and 10 days (1208.30kg/ha) spray regimes. Farmers could therefore adopt either the 7 or 10 days spray regimes in the zone.

Pages 14-17 PDF Full Text
Effects of water and fertilizer stress on the yield, fresh and dry matter production of grain Amaranth (Amaranthus cruentus)

Ejieji, C.J. and *Adeniran, K.A.


The effects of crop yield, fresh and dry matter partitioning of grain amaranth (Amaranthus cruentus) in relation to different water stress and different levels of fertilizer application were studied. Grain amaranth was planted in the predominantly sandy loam soil. The treatments applied include replenishing soil moisture back to field capacity and imposing moisture stress 75% and 50% of the amount of water applied to bring soil moisture to field capacity. Within each treatment were varying levels of fertilizer application based on plant density and influence area at 100%, 75% and 50%. The actual crop evapotranspiration (ETa) was determined by using a weighing lysimeter and the reference evapotranspiration (ETp) was determined by using the pan evapotranspiration method. The results showed that water had significant effect on the total plant weight, stem weight, leaf weight, and root weight with p-values of 0.000, 0.001 and 0.000 respectively. However fertilizer and its interaction with water had no significant effect on total plant weight, stem weight, and root weight with p-values of 0.15 and 0.75, 0.22 and 0.68, and 0.37 and 0.79 respectively. For total plant weight, root, leaf wet and dry weights however, fertilizer had significant effect with p-values of 0.04, 0.042, 0.011 and 0.039 for dry matter.  None of water, fertilizer and their interactions had any significant effect on dry matter concentration and the harvest index of the plant and dry matter concentration of the partitioned components of the plant. Fresh matter accumulation increased with time for all the combinations until after the seventh week of planting beyond which fresh accumulation started reducing. Plots with moisture content kept at field capacity and 100% fertilizer application recorded the highest fresh and dry matter production, while those with 50% of the moisture content at field capacity and 50% of the fertilizer requirement recorded the least fresh and dry matter production.  Yield was highest for plots with the water content kept at field capacity and 100% fertilizer application recording an average value of 22.87 ton/ha and least with plots with 50% of the moisture content at field capacity and 50% of the fertilizer treatment recorded 12.55 ton/ha. The study shows that moisture stress seriously affects grain amaranth than fertilizer stress. Also it shows that the fresh and dry matter accumulation
and yield of grain amaranth depends on the on the soil moisture status.  

Pages 18-24 PDF Full Text
Mitotic index studies on Treculia africana Decne. in Nigeria

Osuji, Julian O*. and Owei, Sweet D. Jnr.


Treculia africana Decne., (African bread fruit; wild jack fruit, or African boxwood), is a neglected and underexploited tropical tree crop belonging to the taxonomic family Moraceae. Mitotic index study was conducted on this species using fresh healthy root tips harvested from germinated seedlings. It was observed that cell division took place at all time in the day and night but took place more in the day time than at night. The most intense period of mitosis was between 2:00 and 6:00 pm with a peak at 4:00 pm (Nigerian Time). Mitotic counts showed that the number of prophase cells decreased when that of metaphase increased as the day progressed. The peak of anaphase was during the early hours of the night at 8:00 pm. The proportion of interphase cells reduced while that of dividing cells increased before the peak of metaphase. Information made available in this work henceforth pave the way for further progress in cytological and cytogenetic research towards improvement of this crop plant.

Pages 25-28 PDF Full Text

January 2010 issue
        [1(1) 2010]
January 2010 issue