Aspetti di tecnica colturale in canapa da cellulosa: densità di semina e concimazione azotata.

Negli anni 1976 e 1977 nell'Azienda di Campulongu (Oristano) è stata esaminata la reattività del1a canapa da cellulosa ad alcuni interventi agronomici. In particolare, nel 1976 sono state poste a confronto 2 cultivar: Fibranova e Superfibra; 3 densità di semina: 40, 6o, 80 Kg/ha di seme; 4 dosi di concime azotato: 8o, 140, 200, 260 Kg/ha di N. Da un punto di vista produttivo non sono emerse differenze fra i trattamenti. Nel 1977 sono state confrontate 3 densità di semina: 40, 6o, 80 Kg/ha di seme e 4 dosi di concime azotato: o, 80, 16o, 240 Kg/ha di N. Le rese di bacchetta non hanno variato in funzione della densità di semina, mentre sono risultate significativamente superiori nelle tesi concimate. L'incremento massimo si è avuto soltanto fra il testimone non concimato e la dose di 80 Kg/ha di N; fra quest'ultima dose e quelle successive le differenze non sono risultate statisticamente significative. Si è messo in evidenza che a una diminuzione della densità di piante per unità di superficie corrisponde incremento nell'altezza e nei diametri delle piante, per cui non si hanno variazioni produttive in funzione del numero di piante per m2. In tutti i casi le rese di bacchette, intorno ai 140-160 q/ha, sono risultate soddisfacenti

Aspetti di tecnica colturale in canapa da cellulosa: epoca di raccolta

In 1977 and 1978 the productive response of hemp pulpe use at various different harvest times was examined at the Ente Nazionale Cellulosa e Carta Campulongu farm (Oristano). In 1977 three different harvest times were compared using the cultivars Superfibra and Carmagnola Selezionata: the first harvesting took piace during female flowering, the second twenty days from the first and the third twenty days from the second. To the three test periods of the previous year a further early harvest was included in 1978, this time during full male flowering. In both years, the best yield tram both cultivars was obtained by harvesting the plant in the time of full female flower, that is in the first ten days of August. There did not appear to be any differences between the two cultivars, while one month's delay in the sowing reduced the 1978 yield as compared to that of 1977

Consumi idrici ed esigenze in azoto della canapa da cellulosa

The cultivation of paper making hemp has raised to new prospects depending on the world crisis of paper, so that in some Country, as France, such cultivation has reached a spreading of about 5.000 hectares, in connection with the new techniques which allow the complete mechanization too. In 1972 and 1973 the Institute of Agronomy of the University of Sassari has studied some aspects of the cultural technique of paper making hemp. The sown, using a hybrid originated from France (R1D7,F36, N), with 60 kg/ha of seed, has been carried out on 8th april in 1972 and on 20th april in 1973. Two water volumes (400 and 800 mc/ha), 3 irrigated intervals (8-12-16 days), 4 doses of nitrogen (0-75-150-225 kg/ha of N) and three times of harvest (3 July, 19 July, 5-6 August) have been compared. The more suitable harvesting time seems to be the second one (19 July) either in 1972 or in 1973. In the limit of this period yields of stalk at 15% of moisture, in the mean of nitrogen treatments, have fluctuated in 1972 from 131,5 q/ha in the thesis with interval of 12 days and unit water volume of 800 mc/ha to II8.3 q/ha with interval of 16 days and unit water volumes of 400 mc/ha; in 1973 yields at the second harvest time in the mean of the N thesis, have fluctuated from 155,3 q/ha in the thesis with interval of 8 days and uni t water volumes of 800 mc/ha to 123,6 q/ha in the thesis with interval of 16 days and unit water volume of 400 mc/ha. In both years the cultivation has reacted positively to N supplies. In the second harvesting time and in the mean of the irrigated thesis, in 1972, we have become from 161,8 q/ha of stalk in the thesis with 225 kg/ha of N to 72,6 q/ha of the test not fertilized; in 1973 differences turned out to be less marked coming from 151,4 q/ha of the thesis 150 kg/ha of N to II 7,3 q/ha of the test. As already told, the time more suitable for the stalks'cut falls in the 2ª decad of July. Consequently the cultural cycle is come out of about 90-100 days. Such a speed in the growth of hemp under Sardinian environment seems to be interesting in relation with the possibility of limiting water consumptions and with the introduction of hemp in intensive cultural arrangement

Effetti della concimazione azotata su frumento duro in un tipico ambiente mediterraneo

After a brief description of the pedo-climatic environment of Sardinia the results of the experiments carried out by the Istituto di Agronomia ge· nerale e Coltivazioni erbacee dell'Università di Sassari and of the Centro Regionale Agrario Sperimentale di Cagliari on the usage of nitrogen fertilization on durum wheat are presented. Some aspects are examined related to the quantities of nitrogen used at the time of supply, various types of fertilizers in relation to seasonal course, the nature of the soil, the preceding cultures and the different cultivars. The effectiveness of the fertilization is closely related to the water reserve, particularly during the biological phases following heading. The production increases, obtained by supplying nitrogen at the moment of sowing or in winter time, are a consequence due mainly to the increased number of ears per surface unit. Positive effects on the productivity of the ear and on the weight of the kernel are observed with a late supply of nitrogen, provided, naturally, that there is in the soil enough water supply. In conditions where there is absence of water even not very high quantities of nitrogen cause a decrease of the yield, consequent to a reduction of the kernel weight. Besides the productive aspects, the effects of the nitrogen are also examined on the qualitative features of the seed, in particular on the yellow berry and on the proteic content

Aspetti di tecnica colturale del cartamo (<i>Carthamus tinctorius</i> L.)

During 1981, 1982 and 1983 trials have bean carried out on different varietas of safflower. The trials con· cerned the sowing rates, row spacing and N fertilization. The varietas Safflola 202, Safflola 541 and Safflola 918 have given the highest yield achieving 20 q ha-1 . Achenes yield hasn't been statistically different using 20-30 and 40 Kg ha -1 of seed. Yield rates nearly equal have been obtained with plants in narrow rows (25 cm) and in wide rows (50 cm). N fertilization has positively affected the achenes-yield. 40 Kg ha -1 of N have determined an increased production wich has been statistically significant in comparison with the non fertilized test. It hasn't been achieved any further increment in the yield using higher N rates (80 and 120 Kg ha-1)

Confronto fra cultivar di soia: un biennio di sperimentazione in Sardegna

During the years 1981 and 1982 a comparison trial among different late planted soybean cultivars has been carried out in the experimental field of «S. Lucia» (OR). Two sowings took place: the first one within the end of May and the second one in the end of June. Fourteen cultivars belonging to the I, II, III and IV ripeness groups have been used in the first sowing, whereas in the second sowing the cultivars were eleven and they belonged to the I, II and III groups. Variable grain yields (tram 30 up to 41 q/ha) have been provided by the I, II and III maturation groups in both sowings. A drying process of grain could be avoided because of the low humidity at the harvesting of the varieties belonging to the I and II groups. The achievements show the real possibility to insert soybean instead of summer sowing cultivation of maize because of maize sensitivity to insects

Il Contenuto di sostanze psicoattive nelle varietà di canapa coltivate

In the years 1978-79, a test has been carried out on european cultivars of Cannabis sativa L. In order to evaluate the content of Δ9-THC in function of genotype, vegetative stage and environment. The experiences have been done in different pedoclimatic environments of northern, central and insular Italy. They have shown that, in spite of the significativness of the differences found emong varieties, sexes, environments and inflorescence collection periods, the content of Δ9-THC 15 is so low (O,037-0,371 %) that it can't induce psicotropic effects. The investigation has moreover put in evidence the high individuai variability (the maximus variability coefficient has been 170%) which denotes the remarkable heterogeneity of the character examined

Aspetti di tecnica colturale in canapa da cellulosa: scelta varietale

During 1976 and 1977 in Oristano, Italy, has been carried out a trial concerning the yield of 5 dioecious (Superfibra, Fibranova, Eletta Campana, Carmagnola, Carmagnola selezionata) and 2 monoecious (Fibrimon 56 e Fedrina 76) cultivar of hemp. The monoecious cultivar were of French origin. The 7 cultivar yielded well with 140-160 q/ha of stalks at 15% of humidity. No difference of mean production of all cultivar has been observed between 1976 and 1977. The number of plants/m2 appeared to be the main factor of yield

Effetti della riduzione degli input di coltivazione sul girasole (<i>Helianthus annuus</i> L.) coltivato in diversi ambienti mediterranei

A two year field experiment was carried out on six different environmental sites of Middle and Southern Italy with the aim of evaluating the effects of some low input cultural techniques on yield of sunflower (Helianthus annuus L.). In each sites sunflower commerciai hybrids were sown at different dates between January to April. Normal and minimum soil tillage were included in the experimental design, and irrigation treatments were also tested in two sites. Yield response of sunflower to minimum tillage treatments did not show in most cases a significant variation in comparison with ordinary tillage methods. Early sowing enhanced or decreased sunflower performance according to the agrometeorological features of the sites. Irrigation determined a significant yield effect but in some cases water efficiency was lower in early sowing treatments. The results indicate the possibility of reducing energy input in sunflower without remarkable yield depression, by adapting cultural techniques and hybrid choice to the environmental characteristics. Due anni di sperimentazione in campo sono stati condotti in sei differenti ambienti dell'Italia Centro-Meridionale al fine di valutare la possibilità di una semplificazione della tecnica colturale in girasole. Sono stati saggiati ibridi di diversa precocità seminati in differenti epoche e sottoposti ad un diverso grado di intensificazione delle lavorazioni. In due delle unità operative (UUOO) sono stati sperimentati anche diversi trattamenti irrigui. Nella maggior parte dei casi la lavorazione ridotta non ha determinato differenze significative di resa rispetto alla tecniche tradizionali di preparazione del terreno, mettendo in evidenza la capacità del girasole di sfruttare l'effetto residuo delle lavorazioni. L'anticipo delle semine ha avuto un effetto sulle rese variabile a seconda del sito di sperimentazione, indicando che in alcuni ambienti questo accorgimento consente di utilizzare al meglio le eventuali piogge invernali e primaverili. L'eliminazione o la riduzione degli apporti irrigui ha invece determinato significative riduzioni di produzione, anche se in alcune situazioni questo effetto è risultato meno marcato con le epoche di semina anticipate. Il primo biennio di sperimentazione ha messo in evidenza che la riduzione degli input nella coltivazione del girasole sia proponibile anche dal punto di vista economico purché si adegui la scelta delle tecniche colturali e dei genotipi alle caratteristiche ambientali

Possibilità di sviluppo della coltivazione del sorgo per l'alimentazione del bestiame in Somalia

In 1979, a trial concerning yield differences between 2 different periods of harvesting (soft dough and complete maturation of the grain) of a sorghum hybrid BR has been carried out in Afgoy (Somalia). The effects of four nitrogen level have been also evaluated. The results show no effect of different nitrogen levels on total dry matter production and grain quality. Maximum dry matter yield and maximum F.U. production has been reached at complete maturation of the grain. General level of grain yield has been restricted in consequence of bird damage in spite of the presence of the gene BR