IRANIAN JOURNAL OF HORTICULTURAL SCIENCE AND TECHNOLOGY
Year:2004 | Volume:5 | Issue:1|Papers Count:8

Self-compatibility appears to be low in some European and most Asian cultivars of apricot fruit. Therefore, some other pollinizer cultivars should be used for commercial fruit production. An experiment was conducted to determine the effect of male pollen source on fruit traits of main apricot cultivars at Sahand Horticultural Research Station during 2001-2002. The experiment was carried out in the controlled conditions and the design of experiment was set up in RCB. The results indicated that the pollen type had significant effects on weight, size, time of ripening and flesh thickness. However, the pollen source had no effect on both total soluble solid and kernel taste.

Concentrations of K, Na and Cl ions under salinity treatments, in seedlings of five citrus rootstocks, Bakraii (mandarin × sweet lime), Volkamer lemon (Citrus volkameriana) sour orange, sweet lime and Mexican lime were studied in a glasshouse, using a randomized complete block design with factorial arrangement and four replications. One-year old seedlings of each rootstock were grown in pots, containing native soil (pH=8.2) and irrigated with water supplemented with 0 (control), 20, 40 and 60 mM NaCl. At the end of experiment, concentration of K, Na, and Cl ions in shoots and roots were determined and Na/K ratio calculated. Concentration and distribution of K, Na and Cl ions were significantly varied in control and other treatments. Salinity increased concentration of Cl and Na ions in shoot and root, but the rate of increase varied among rootstocks and treatments. Increasing the rate of NaCl decreased K concentration in some rootstocks but increased it in other elements. The highest Na/K ratio was observed in shoot of sweet lime and roots of sour orange, Bakraii and volkameriana and the lowest Na/K ratio was found in shoot of volkameriana and roots of Mexican lime and sweet lime.

Iron deficiency that usually appears as chlorosis in young leaves, is considered to be one of the most important nutritional disorders in citrus trees, particularly in calcareous soils, that seriously reduces yield and fruits quality. Selecting the resistant rootstocks to iron chlorosis is one of the most important approaches to prevent this nutritional problem. Therefore, an experiment was carried out at Jahrom Agricultural Research Station, the effects of resistant rootstocks like Macrophylla (Citrus macrophylla Wester), Volkamer lemon (Citrus volkameriana), and Sour orange (Citrus autantium) in comparison with prevailing Sour lime (Citrus aurantifolia Swing) rootstock and also their interactions with scions like ‘Valencia’ orange, ‘Washington Navel’ orange, Jahrom local orange and red pulp orange (Moro) were investigated. Also the effects of sequestrene 138 Fe in three levels 0 (control), 5 and 10 gram per tree were compared. The Macrophylla and Sour orange rootstocks had the best positive and significant effects in increasing the scions leaf chlorophyll index at 1% statistical level. Mocrophylla also had the highest iron absorption. The interaction between rootstocks and sequestrene 138 Fe showed that the application of sequestrene 138 Fe levels on Macrophylla rootstock did not have a significant effect on leaf chlorophyll index at 1% statistical level, therefore Macrophylla had high potential in increasing scions leaf chlorophyll index without any use of sequestrene 138 Fe as fertilizer. Sour orange had lower iron absorption than other rootstocks, but significantly increased scions leaf chlorophyll index. In contrast, Sour lime with high potential for iron absorption had little effect on scion leaf chlorophyll index. This, did not only clearly showed the effect of  rootstocks on scions leaf iron chlorosis Paradox, but also indicated that the effectiveness of rootstock in resisting iron chlorosis is related to mechanisms other than the extent of iron absorption by the roots. Macrophylla significantly increased iron, zinc, manganese and copper absorption comoared to other rootstocks at 1% statistical level; moreover, it absorbed the highest rates of phosphorus and potassium and a consideralde rate of nitrogen. This high absorption potential of Macrophylla put it in the group of effective rootstocks for Jahrom. The results of the experiment also demonstrated the significant difference between scions on resistance against iron chlorosis, i.e., the navel and local orange had high chlorophyll index irrespective of the rootstock used. In contrast, the scions like red pulp and ‘Valencia’ orange had lower chlorophyll index and were affected by the rootstock more than others. For example in comparison with Sour lime, the Macrophylla rootstock increased red pulp orange (Moro) leaf chlorophyll index about 18 percent.

In spite of the advantages of native onion (Allium cepa L.) cultivars, commercial seed production of these cultivars has its own difficulties in our country. Therefore, every year large amount of seed is imported. One of the main problems in seed production of onion is pollination and fertilization of their flowers. Insects including honeybees are the main pollinators of onion flowers. In order to study the effects of insects, especially honeybees on onion seed yield and quality, a split plot experiment in a complete randomized block design with three replications was used. Main plots consisted of ten onion cultivars and sub-plots consisted of open pollination and non-pollination in cages. Results showed that seed yield per inflorescence in the presence of pollinators, was 2.4 times of non-pollinated inflorescences (in cages and without pollinator presence). Pollination effect on weight of 1000 seeds was negligible. Germination percentage of seeds produced in open pollinated plots was 7% higher than those of non-pollinated plots. Germination mean hours for seeds of pollinated plots were 10.6 hr less than seeds of non-pollinated plots. Seedling dry weight from pollinated plots was higher than non-pollinated plots. There was a significant difference between cultivars regarding seed yield per seed stalk. ‘Ghom’ and ‘Horand’ cultivars produced highest and lowest seed yield, respectively. Due to interaction between pollination and cultivars, effect of pollination varied among cultivars. Also there were significant differences between cultivars regarding weight of 1000 seeds, germination percentage, germination rate of seeds and seedling dry weight.

In sodding method, seed germination rate and sod quality are affected by culture media and sod netting materials. In this research the effects of three culture media (clay, 10:1 v/v mixture of fine sand/palm waste and 10:1 v/v mixture of fine sand/mushroom compost) and four sod netting materials (plastic mesh, kenaf-based mat, palm fiber and a control) on seed germination rate, turf shoot density and amount of weed m-2, were studied at Experimental Station of Horticultural Department, University of Tehran in 2001. Experiment was conducted as a 3×4 factorial in a complete randomized design with 12 treatments and 3 replications. Turfs used in this trial was sport type consisted of Lolium prene cv. Taya (40%), Poa pretenses cv. Wembly (30%) and cv. Sobra (10%) and Festuca rubra cv. Diego (20%). Results showed that in clay bed, germination rate was significantly less than sand mixes. Application of palm fiber increased germination rate in all treatments. Clay bed and also palm fiber netting system showed more weeds significantly. Clay and fine sand-palm waste media showed the highest and lowest shoot density, respectively. Palm fibers as netting increased shoot density.

The effects of different cucurbit rootstocks, pumpkin (Cucurbita pepo L.), Cucurbita moschata L. and fig leaf gourd (Cucurbita ficifolia) were studied on cucumber (Cucumis sativus L.) scion cv. Sultan in 2002. Grafting method was whole insertion grafting’. This experiment consisted of four treatments (three rootstocks and a control) with three replications using randomized complete block design (RCBD). Some vegetative and quantitative characteristics such as main stem length, number of leaves, vine yield, fresh and dry weights of air organs, fresh and dry weights of root and percentage of fruit dry matter were measured. The results showed significant differences in vegetative characteristics between grafted and ungrafted plants (P<0.01), except for fruit dry weight among the rootstocks and Cucurbita pepo had the greatest effect. Productivity was affected by rootstocks, Cucurbita pepo showed the highest yield (4.5 kg vine-1), 33% yield increasing, but Crookneck and control had the lowest yield (3 kg vine-1) compared to 4 kg vine-1 in fig leaf gourd rootstock (12% increase in yield).