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Effect of different tillage methods on soil physical properties and crop yield of watermelon (Citrullus vulgaris)

Majid Rashidi and Fereydoun Keshavarzpour

A two year field experiment was conducted to investigate the effect of different tillage methods on soil physical properties and crop yield of watermelon. Tillage treatments in the study were moldboard plow + two passes of disk harrow as conventional tillage (CT), two passes of disk harrow as reduced tillage (RT), one pass of disk harrow as minimum tillage (MT) and no-tillage (NT) as direct drilling method. The statistical results of the study indicated that tillage method significantly (P≤0.05) affected crop yield, fruit weight, fruit length, fruit diameter and total soluble solids, but there was no significant differences in other components such as number of plants per hectare, number of fruits per plant, root length and root dry matter. The maximum value of crop yield (21.11 t ha^-1), number of plants per hectare (2730), fruit weight (5.15 kg), fruit diameter (20.3cm), root length (42.0cm) and root dry matter (54.1%) was observed in case of CT treatment, while maximum value of number of fruits per plant (1.56), fruit length (23.0cm) and total soluble solids (7.8%) was noted in case of RT treatment. On the other hand, the minimum value of crop yield (12.26 t ha^-1), number of plants per hectare (2590), number of fruits per plant (1.40), fruit weight (3.38kg), fruit length (20.7cm), fruit diameter (17.9cm), root length (37.1cm) and root dry matter (46.5%) was obtained in case of NT treatment, while the minimum value of total soluble solids (6.6%) was noted in case of MT treatment. The statistical results of the study also indicated that tillage method significantly affected soil physical properties. The soil of the CT treatment had consistently the highest moisture contents (19.6%) and the lowest bulk density (1.41g) and penetration resistance (560kPa); while the soil of the NT treatment had the lowest moisture contents (16.8%) and the highest bulk density (1.52g) and penetration resistance (1250kPa). Accordingly, moldboard plow followed by two passes of disk harrow was found to be more appropriate and profitable tillage method in improving soil physical properties and crop yield of watermelon.

Chemical and non-chemical thinning methods in apple (Malus domestica Borkh)

George Ouma

Thinning trials were conducted in the apple orchards of Klein Altendorf Experimental Station Bonn, Germany using 7-year-old CV. ‘Cox orange’ and CV ‘Elstar’ apple trees in the year 2001 and 2002. The objectives were to find the effects of treatments on fruit set, yield, quality (i.e. fruit size) and to investigate how photosynthesis and transpiration are affected by one of the chemical thinners. The chemical thinning methods applied in the year 2001 were Ethrel (Flordimex) at 500ml/ha, Ethrel at 1000ml/ha, Ammonium Thiosulphate (ATS) sprayed to flowers on one year old shoots (ATS 1), Ammonium Thiosulphate (ATS) sprayed to flowers on older shoots (ATS 2), Amidthin plus Telmion, Amidthin plus Ethrel and unsprayed control. In 2002 the chemical thinning treatments applied were Azolon fluid (Urea formaldehyde), sprayed at 7.5li/ha and Ethrel (Flordimex) sprayed at 300ml/ha and unsprayed control. The non-chemical thinning method which was only applied in 2002 was partial defoliation of leaves. The experimental design used was randomized complete block design with three replications. The results showed that in the year 2001 Ethrel at 1000ml/ha had 67% thinning effect while Ethrel at 500ml/ha had 40% thinning. The other treatments had no thinning effect. Amidthin plus Ethrel had 22% yield reduction while Ethrel at 1000ml/ha had 30% yield reduction. ATS 2 had 44% increases in yield while ATS 1 had no effect. In terms of fruit size Ethrel 1000ml/ha had the best fruit quality (i.e. preferred diameter class of 70mm), followed by Amidthin plus Ethrel, Amidthin plus Telmion and Ethrel at 500ml/ha. In the year 2002 Azolon fluid resulted in 55% thinning in the first fruit set count before June drop while Ethrel had 56% and Azolon plus Ethrel 54% thinning effects which were not significantly different from defoliated treatment. Similar thinning trends were observed for fruit set counts after June drop. Transpiration and photosynthetic rates were reduced by 5% and 20%, respectively. Ethrel at 300ml/ha reduced yield significantly from 29.2kg/ha in the control to 25.5kg/tree while methylene urea (Azolon) had no effect. Thinning with methylene urea increased fruit size to 67% and Ethrel (Flordimex) to 79% of fruits larger than 70mm. It is concluded the chemical treatments thinned the fruits adequately and were not significantly (P< 0.05) different from the non-chemical methods of thinning and fruit size was improved while transpiration and photosynthesis were slightly affected after Azolon application.

Growth and physiological attributes of Ceiba pentandra (L.) gaertn. seeds and seedlings under salt stress

R. Rex Immanuel and M. Ganapathy

Establishing salt tolerant multipurpose tree plantations on saline soils may improve fertility status of the soil and uplift the status of farmers in semiarid environments. Because of wide range of uses of Ceiba pentandra (L.) Gaertn., it has been cultivated for a long time, but issues related to suitability on salinity are less documented. Thus, to study the salt tolerance of Ceiba pentandra, the effect of salinity on germination, vigour index of germinated seedlings, growth, chlorophyll stability index (CSI) and ionic uptake of seedlings were examined. The seed germination, morphological and physiological parameters were slightly affected by 3 to 9dSm^-1 salinity concentration, but were markedly reduced on the 12 and 15 dsm^-1 salinity concentrations. Higher salinity concentration shows lower chlorophyll stability index this leads to decrease photosynthetic rate and less dry matter production. Rising of salinity in soil solution increased ionic concentration in the leaf tissue leading to reduction in leaf size leaf chlorosis, scorching of leaves, withering and finally death of seedling was occurred. However the Ceiba pentanda seeds germinate and tolerate the salinity variant of up to 9dSm^-1, which can be regarded as a LD₅₀ value for severe damages and classified as moderately saline tolerant multipurpose tree species in seedling stage.

Determination of kiwifruit volume using image processing

Majid Rashidi, Keyvan Seyfi and Mohammad Gholami

Kiwifruit (Actinidia deliciosa) volume was determined using water displacement and image processing methods. Surface images of each kiwifruit, captured with a digital camera, were utilized in the image processing method. The volume determined from image processing method (IPM) was compared to the volume determined by the water displacement method (WDM) using the paired samples t-test and the Bland-Altman approach. The paired samples t-test results showed that the volume determined by image processing method was not significantly (P > 0.05) different from the volume measured by water displacement method. The mean difference between water displacement and image processing methods was -2.23 cm³ (95% confidence interval: -6.71 and 2.25 cm³; P = 0.304). The standard deviation of the volume differences was 8.10 cm³. The Bland-Altman approach also indicated that for all sized kiwifruits, image processing method satisfactorily estimated kiwifruit volume. Accordingly, image processing provides an accurate, simple, rapid and non-invasive method to estimate kiwifruit volume and can be easily implemented in monitoring growth development under various management practices and sorting of kiwifruits during post-harvest processing.

Growth parameters, photosynthesis, stomatal conductance and chlorophyll content of avocado (Persea americana) rootstock seedlings as affected by different container sizes and different levels of irrigation frequency

George Ouma

Studies were conducted at Maseno University, Kenya from July 2003 to March 2005 to investigate the effect of four container sizes; V₁ (1.7 litres), V₂ (2.7litres), V₃ (3.9 litres), V₄ (4.7 litres) and three irrigation frequency levels namely W₁ (irrigating every day), W₂ (irrigation every 2 days, W₃ (irrigation every 3 days in a polythene- covered greenhouse on the morphological and physiological parameters of Avocado (P. americana) rootstock seedlings. The experimental design was completely randomized replicated four times. Morphological and physiological parameters were determined using standard methods and they were number of leaves, plant height, stem diameter, shoot and root dry and fresh weights, whole plant dry and fresh weight, CO₂ assimilation rate, substomatal CO₂ concentration, soil respiration, transpiration rate and stomatal conductance. Both irrigation frequency and container size significantly increased these parameters and the interaction between them was either significant or not depending on the parameter.

Physico-chemical analysis and effect of distillery effluent on seed germination of wheat (Triticum aestivum), pea (Pisum sativum) and lady finger (Abelmoschus esculentus)

Sandeep K. Pandey, Pallavi Tyagi and Anil K. Gupta

A laboratory work was undertaken to assess the waste water quality parameters of treated distillery effluent and their effect of various concentrations like 0%, 25%, 50%, 75% & 100% on seeds germination, speed of germination, peak value and germination value of three selected seeds i.e. Wheat (Triticum aestivum), Pea (Pisum sativm) and Lady Finger (Abelmoschus esculentus). Where the high value of T.S. (4285), B.O.D. (544.5) and C.O.D. (2433) indicates the high inorganic and organic load. Germination percentage decreases with increasing concentration of effluent in all the tested seeds, where as the germination speed, peak value and germination value increases from control to 25% and 50% concentration and decreases from 50% to 75% and 100% effluent. To estimate the probable liquid fertilizer benefit, studies on subsequent dilutions is needed to corroborate the present study. 

Municipal solid waste management in Ghazipur city- A case study

Sandeep K. Pandey, P. Tyagi and Anil K. Gupta

Status of the municipal solid waste (MSW) of Ghazipur city was studied. The results indicated that the organic waste was the highest among other components of the wastes. A considerable proportion of organic carbon was found which causes the health problem to the workers. In order to avoid this situation small community pots with revolving axis are needed along with the disposal vehicles, small auto rickshaws or paddle tricycles to maximize the collection of wastes. Annual report of the addition of wastes due to increasing population and the strategies for collection of wastes shall have to be formulated.